Originally Posted by
salut0
Is is possible to use Avios to upgrade the reservation to Y+ and then do an AUP or POUG from there to J?
You need to be booked in Y, B, H to upgrade using Avios. (usually more expensive than just booking T) The BA codeshare also makes things messier, although maybe BAEC can do something that IB+ wouldn't... In any event, you will need PE award space.
I recommend that you put away the Expertflyer and just monitor your booking regularly for possible upgrade offers...